Metal panels of this type have been known in the art. The panels function solely to provide a weatherproof exterior sheathing of the buildings and do not provide any structural support. The panels are conventionally made of a relatively thin material which does not provide any substantial heat insulation to the building or structural support. In an effort to reduce material costs, various vinyl siding manufacturers have reduced the thickness of their siding panels. However, subsequent performance and appearance complaints have caused the industry to establish a minimum thickness of 0.035". Accordingly, it has been proposed to back such panels with board like members of heat insulating material. Although insulating material has successfully been laminated to aluminum siding, inherent problems were associated with the lamination of insulating material for vinyl siding.
Unlike aluminum and steel siding which can be manufactured with flat faces, vinyl siding has to be manufactured with an unnatural appearing concave face. The concave or mechanical set face was introduced to vinyl siding panels to reduce or eliminate the occurrence of oil canning. Oil canning is a condition where unacceptably large bubbles or distorted areas appear on the face of the siding panel. Oil canning occurs during changing temperature and weather conditions when the vinyl expands and contracts; and because the vinyl is thin and cannot maintain its own shape. The mechanical set of a concave face diminishes the oil canning problems which have presented substantial warranty costs to the industry. However, this problem has caused the industry to limit the exposure of the horizontal siding to ten or eleven inches. (A ten inch exposure provides two five inch faces.) Vinyl panels wider than 10-11" have been withdrawn from the market because the panels failed to perform up to industry standards. Despite the improvements, oil canning continues to represent significant customer dissatisfaction and warranty claims.
For added insulation, aluminum siding jobs used drop-in backer boards. Initially, the same foam drop-in backer boards were also used for vinyl siding jobs, but were quickly prohibited by vinyl siding producers. The flat surfaces associated with the thin drop-in foam insulation tended to straighten out the concave set placed in vinyl siding faces to resist oil canning. The flat surface drop-in insulation material had been designed specifically for use with aluminum siding and was not configured to be compatible with the new concave set of the vinyl faces. Further, mechanical binding or obstructions developed between the vinyl and insulation materials at some job sites, because of poor application techniques. Because the previous drop-in foam insulation panels were thin and lacked a registration point, it was easy for the applicator to drop the backer board into the vinyl siding lock mechanism. Then, when the vinyl siding panel was locked into place, the backer board would be trapped in the vinyl siding's interlocking mechanism, thereby restricting the movement of the vinyl siding panel. As a result, the vinyl siding industry banned the use of drop in backer boards. The vinyl siding panel needs to freely move to accommodate its high coefficient of expansion and contraction. If the backer board was trapped in the interlocking mechanism, further distortion occurred in the vinyl siding. In addition, the drop-in backer boards were not manufactured with a consistent thickness. The foam thickness was often varied from run to run and manufacturer to manufacturer resulting in a unacceptable, uneven, poorly appearing wall.
Another problem relating to the lamination of vinyl siding and insulating material is a condition called "telegraphing". This is a condition that occurs when the adhesive glue line is seen under certain lighting conditions through the face of the siding. The telegraphing condition provides an unacceptable appearance. Therefore, a different adhesive and application system is required to solve the telegraphing problem. At the same time it is necessary to provide an adhesive that is compatible with both the vinyl and insulation material and will hold the siding faces to the insulation material for the entire life of the vinyl siding. In addition, the adhesive must remain flexible throughout the entire life of the composite product.
Another problem occurring in the industry with the vinyl siding installed over current insulation materials is that the vertical edges of adjacent vinyl siding panels often do not lay flat as a result of the deformation of the shape of the vinyl due to improper manufacturing, handling or installation. The resulting open lap is unacceptable from an aesthetic standpoint and, the siding panels can be subject to water, dirt and debris, as well as air infiltration.
Still another problem occurring in the industry with the insulation material is that the vertical edges of adjacent drop-in backer board insulation panels do not provide adequate insulation and structural strength for the vinyl. The current drop-in backer board insulation does not provide a seal between vertically adjacent vinyl siding panels since the insulation material does not extend to the vertical edges.